Using risk factors to help in the diagnosis of acute myocardial infarction in patients with non-diagnostic electrocardiogram changes in emergency department

Objective: This study aimed to determine the association of cardiac risk factors and the risk of Acute Myocardial Infarction (AMI) in Emergency Department (ED) patients with non-diagnostic ECG changes. Methods: This cross-sectional study was conducted in the ED of Imam Hossein Hospital during a period of one year. In this study, patients with symptoms suggestive of AMI including chest pain, dyspnea, palpitation, syncope, cerebrovascular incidents, nausea, vomitting, dizziness and loss of consciousness were included. The demographic data and risk factors, such as age, gender, history of diabetes, Hypertension (HTN), Hyperlipidemia (HLP), renal failure, positive family history of Coronary Artery Disease (CAD), smoking, substance abuse, alcohol consumption within the past 24 hours and cocaine use within the past 48 hours were recorded. Non-diagnostic ECG included: normal, non-specific, abnormal without ischemic symptoms such as old bundle branch block, Left Ventricular Hypertrophy (LVH), etc. The final diagnosis of AMI was determined by Creatine Phosphokinase-MB (CPK-MB) serum markers and Troponin I. The data were analyzed by using SPSS V. 20 and the level of statistical significance was considered to be P< 0.05. Results: HTN, HLP, family history of heart disease were significantly higher in those who had non-diagnostic ECG (P< 0.05). However, the ischemic heart diseases were significantly lower in those with non-diagnostic ECG. History of diabetes, stroke, renal failure, alcohol or opium and menopause showed no significant association with non-diagnostic or diagnostic ECG. Conclusion: Overall, the risk factors are limitedly associated with the occurrence of Myocardial Infarction (MI) in cases where ECG is not diagnostic and it is better to use other criteria to diagnose AMI.